Vegetarians have a Lower Cancer Rate than Regular Meat-Eaters

I always find it amusing when I’m reading nutrition propaganda from someone using outdated information and they say something like, “As far back as [date], we knew that…” And so it disappoints me to have to do the same thing right now: As far back as June, we knew that vegetarians had a lower cancer rate than regular meat-eaters; it’s just that it’s taken me until now to update VeganHealth.org and post about it.

And, why am I saying “regular meat-eaters” rather than just “meat-eaters”? Because, in this report from EPIC-Oxford (1), the people who ate no meat other than fish had an even lower cancer rate than the vegetarians, in comparison to the regular meat-eaters. Here are the rates as compared to regular meat-eaters:

Vegetarians .88 (.81, .96)
Fish-eaters .82 (.73, .93)

Now before anyone says that fish-eaters, therefore, had a lower cancer rate than the vegetarians, let me point out that a cursory glance at those confidence intervals indicates to me that there would not be a statistically significant difference if you compared the vegetarians to the fish-eaters; but the study did not report testing for that.

When breaking the cancers down into categories, in comparison to the regular meat-eaters, the vegetarians had lower rates of stomach (.36, .16-.78), bladder (.47, .25-.89), and lympthatic & hematopoietic tissue (.55, .39-.78) cancer. They had a higher rate of cervical cancer (2.08, 1.05-4.12).

In comparison to the regular meat-eaters, the fish-eaters had lower rates of colorectal (.77, .53-1.13), prostate (.57, .33-.99), and ovarian (.37, .18-.77) cancer. They didn’t have a higher rate of any cancer.

So, can we now say that vegetarians have a lower rate of cancer than meat-eaters? Well, fish-eaters are meat-eaters, so that might be kind of hard. We could say that vegetarians have a lower rate of cancer than chicken eaters.

To see more of the numbers and details, as well as results from other studies on vegetarians and cancer rates, click here.

This entry was posted on Friday, August 14th, 2009 at 5:28 pm and is filed under Cancer. You can follow any responses to this entry through the RSS 2.0 feed.
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13 Responses to “Vegetarians have a Lower Cancer Rate than Regular Meat-Eaters”

I wonder if there are correlation/causation issues? It may be that vegetarians and fish-only carnivores disproportionately have other healthy habits. I know that’s turned out to be a problem with studies on the health effects of moderate drinkers–it turns out that one-drink-a-day folks are an unrepresentative population, with enough other healthy habits (regular exercise, moderate eating) that it’s hard to tease out the health benefits, if any, of the alcohol itself.

It would be nice if they would adjust for dairy consumption. However, there have been many studies looking at dairy consumption and cancer, and the results have been fairly mixed. In the studies I’ve seen that have compared the eating habits of lacto-vegetarians to meat-eaters, the lacto-vegetarians have not eaten more dairy than the meat-eaters.

When they refer to “vegetarians” above, I am assuming they are candidates that consume dairy & eggs. I think that is why the study leans in some cases to benefit fish eaters. If the study were to be “vegans” instead of “vegetarians”, I have a feeling the results would probably indicate a vegan diet would result in the lowest cancer rate across the board.

As someone who now takes vegetarian DHA, I would be interested in finding out what substance in fish seems to confer additional protections. I had read that eating lots of tomatoes and tomato sauce lowered rates of ovarian and prostate cancer.
The higher rate of cervical cancer seems bizarre!

There isn’t necessarily any substance in fish other than the omega-3s. We can assume that few of the vegetarians in the study above are making much of an effort to increase their omega-3 intake, and very few of them are taking DHA. So, that could explain the difference.